Arlington County and the City of Alexandria have been working with a citizen task force for several years to plan the Four Mile Run Restoration Project. On Wednesday, May 20, members of the Arlington County Board, the Alexandria City Council and the joint task force on Four Mile Run gathered near the Mount Vernon Bridge for the official groundbreaking of the restoration project.
The first projects from the Master Plan will be constructed in 2015. There are three sites where work will be completed. Site 1 is the area near the Mount Vernon Bridge. The work in this area will include creating an area in the stream for sediment to collect, where it can be easily removed instead of being washed further downstream. Some structures called “J-hooks” will also be constructed in the stream. A J-hook is a curved line of rocks installed in the stream that help to direct the stream flow towards the center of the channel.
Site 2 is the Arlington side of the stream, extending from the Mount Vernon Bridge to Route 1. The work in this area will include removing the large stones along the stream bank, terracing the banks, and replanting with native plants. Structures known as “living shorelines,” which are small breakwaters made of stone with wetland plants behind them, will be installed along the bottom of the stream bank. A viewing platform will be constructed along the stream bank as well. The native plants will include pickerelweed, arrow allum, three-square, bee balm, common rush, black-eyed susan, mountain mint, goldenrod, and more. A coffer dam will be constructed in the stream to divert the stream flow around the work area during construction.
Site 3 is the wetland area on the Alexandria side of the stream. The wetland will be restored to its historical condition. The area will be graded, invasive plants removed, native plants planted, and a new pervious trail will be constructed. The plants include yellow pond-lily, annual wild rice, arrow allum, rose mallow, square-stemmed monkey flower, blueflag iris, river bulrush, and more. There will not be any long-term road or bike trail closures on the Arlington side during construction. There may be short stoppages with flaggers on the bike trail as construction vehicles cross the trail. There will be increased truck activity around the site as construction vehicles deliver and remove materials. There will be a bike trail detour on the Alexandria side near the soccer field.